Is fact catching up with science fiction?

Andy Weir, author of The Martian, tells Guy Kelly the discovery of life would be the ultimate plot twist.

Seven years ago, Andy Weir’s debut, self-published novel The Martian – about a US astronaut who becomes stranded alone on Mars in 2035 – left readers breathless, and the Matt Damon film adaptation did the same at the cinemas three years later.

This week, as science and sci-fi got closer, what did Weir think?

“It’s a very cool breakthrough, but there are immediate questions about whether finding liquid water on Mars means any more than that,” he said.

“If there is life, how is it getting energy? And why haven’t we seen evidence of it before?

“Still, it is worth sending a probe down there, if only because a place with water is the most likely to have fossils of any previous life, but I wouldn’t expect to find anything.

“Think about it: if you grab a fistful of earth anywhere on our planet, it’s teeming with life of some kind. It gets everywhere, and adapts.

“We’ve been sending probes to Mars for a long time, and so far . . . nothing. To me it seems a sterile planet.

“If we did find something, though, it would be the biggest news story of our lifetime.

“You’d see an immediate spike in funding for space exploration: right now, it isn’t cost-effective to try to send someone to Mars, but when it is, a human geologist could do more work in a day than all the robots before it ever have.

“The difference between machines and someone thinking and making decisions is massive.

“There’s no better robot than a scientist. And when it looks possible, there will be a race to be the first country to say ’we did it first’.

“You’d soon also have an issue of how to access Mars without damaging the life on there, and very quickly see a mission to get a sample.

“After that, it would depend on whether the new life is a product of panspermia – the theory that life on Earth originated from chemical precursors in outer space – or started as a second genesis.

“Both would be exciting. Above all, though, finding life on Earth and Mars, two planets in eight, would mean the rest of our solar system must be riddled with life.”

Andy Weir is author of The Martian. His latest novel, Artemis, is out now in paperback (Del Rey, £7.99). – The Sunday Telegraph